Technological advances have made possible wireless communication devices that are small, inexpensive and energy efficient, thus increasing their portability and convenience. Many applications, such as two-way radios, cellular phones, wi-fi, sensor networks, and others, use networks of mobile, often hand-held, wireless communications devices (referred to herein generically as network “radios” or “nodes”).
A common requirement of most wireless communication network applications is some level of time synchronization. The synchronization scheme can vary from lenient to strict. Various media access control (MAC) protocols have been developed that implement variations of time synchronization to achieve collision-free data transfers among the radios.
One challenge for synchronization methods in wireless networks is energy conservation. Another challenge is accommodation of additions, failures, and absences of nodes of the network. Additionally, the synchronization method must be secure against attack.
In the past, the on-board clocks used to achieve time synchronized media access have had a relatively large footprint, have been expensive, and consume significant power. The advent of the chip scale atomic clock (CSAC) has resulted in the potential for highly stable clocks with lower size, weight, power, and cost requirements.